X-ray laser seeding for short pulses and narrow bandwidth

2004 ◽  
Author(s):  
W.S. Graves ◽  
M. Farkhondeb ◽  
F.X. Kaortner ◽  
R. Milner ◽  
C. Tschalaer ◽  
...  
Keyword(s):  
Short Pulses ◽  
X Ray ◽  
Narrow Bandwidth

Transient Collisionally Excited X-ray Lasers Pumped with One Long and Two Short Pulses

2015 ◽  
pp. 53-59
Author(s):  
D. Ursescu ◽  
G. Cojocaru ◽  
R. Ungureanu ◽  
R Banici ◽  
L. Ionel ◽  
...  
Keyword(s):  
Short Pulses ◽  
X Ray

scholarly journals Utilization of Photoconductive Gain in a-Si:H Devices for Radiation Detection

1995 ◽  
Vol 377 ◽  
Author(s):  
H. K. Lee ◽  
J. S. Drewery ◽  
W. S. Hone ◽  
T. Jing ◽  
S. N. Kaplan ◽  
...  
Keyword(s):  
Dark Current ◽  
Radiation Detection ◽  
Current Level ◽  
Current Gain ◽  
Applied Bias ◽  
Device Structure ◽  
Short Pulses ◽  
X Ray ◽  
Photoconductive Gain ◽  
Energetic Charged Particle

ABSTRACTThe photoconductive gain mechanism in a-Si:H was investigated in connection with applications to radiation detection. Various device types such as p-i-n, n-i-n and n-i-p-i-n structures were fabricated and tested. Photoconductive gain was measured in two time scales: one for short pulses of visible light (< 1 μsec) which simulates the transit of an energetic charged particle, and the other for rather long pulses of light (1 msec) which simulates x-ray exposure in medical imaging. We used two definitions of photoconductive gain: current gain and charge gain which is an integration of the current gain. We found typical charge gains of 3 ∼ 9 for short pulses and a few hundred for long pulses at a dark current level of 10 mA/cm2. Various gain results are discussed in terms of the device structure, applied bias and dark current.

scholarly journals Research at the NSF STC for Biology with X-ray lasers

2014 ◽  
Vol 70 (a1) ◽  
pp. C296-C296
Author(s):  
John Spence
Keyword(s):  
Radiation Damage ◽  
Bragg Diffraction ◽  
Cubic Phase ◽  
Short Pulses ◽  
X Ray ◽  
Fast Solution ◽  
Linac Coherent Light Source ◽  
New Ideas ◽  
Diffraction Patterns ◽  
Dynamic Structures

"The NSF BioXFEL Science and Technology Center (STC) is a new consortium of six research campuses devoted to the application of x-ray free-electron lasers (XFELs) to structural biology. Over the last four years a variety of approaches have been made to the observation of protein structure and dynamics for various classes of proteins. The Linac Coherent Light source at SLAC, the first hard-Xray EXFEL, provides intense coherent hard X-ray pulses at 120 Hz which vaporize protein when focussed to a sub-micron beam. Atomic-resolution Bragg diffraction patterns are nevertheless obtained using 50 fs pulses prior to the onset of significant damage, in this ""diffract-then-destroy"" mode, which outruns radiation damage. This use of short pulses instead of freezing samples to reduce radiation damage therefore opens the way to the study of protein dynamics at room temperature in a native environment. I'll review the work of several groups using a range of approaches to different types of sample, including the following: 1. Differences between the frozen sychrotron structure of GPCR proteins and the RT XFEL structure [1]. 2. Pump-probe dynamic structures in Photosynthesis [2]. 3. XFEL study of 2D protein crystals [3]. 4. Prospects for improved resolution in XFEL imaging from single particles such as viruses, where patterns can be obtained from a single virus. 5. New ideas - the Lipid Cubic Phase injector (which allows protein nanocrystals to be studied also at sychrotrons) [4], prospects for fast Laue diffraction using coherent attosecond X-ray lasers, ab-initio phasing [5], the use of angular correlation functions for analysis of fast solution scattering, and two-color opportunites for serial femtosecond crystallography (SFX). See [6] for a recent review of the field. 1. W.Liu et al Science 342, 1521 (2013) 2. A.Aquila et al Optics Express 20, 2706 (2012) 3. M.Frank et al IUCrJ (2014) In press. 4. U.Weierstall et al Nature Comms. (2014) In press. 5. J. Spence et al Optics Express 19, 2866 (2011). 6. J. Spence et al Rep. Prog. Phys. 75, 102601 (2012)."

scholarly journals High power, short pulses ultraviolet laser for the development of a new x-ray laser

1989 ◽  
Author(s):  
L. Meixler ◽  
C.H. Nam ◽  
J. Robinson ◽  
W. Tighe ◽  
K. Krushelnick ◽  
...  
Keyword(s):  
High Power ◽  
Short Pulses ◽  
Ultraviolet Laser ◽  
X Ray

scholarly journals Solid-target seeded soft X-ray laser for short pulses and optical vortex amplification

2021 ◽  
Author(s):  
Olivier Guilbaud ◽  
Alok-Kumar Pandey ◽  
Elsa Baynard ◽  
Irene papagiannouli ◽  
Fabrice Sanson ◽  
...  
Keyword(s):  
Optical Vortex ◽  
Solid Target ◽  
Short Pulses ◽  
X Ray

scholarly journals Генерация аттосекундного импульса на основе коллективного спонтанного излучения слоя трехуровневых атомов, возбуждаемых парой униполярных импульсов

2020 ◽  
Vol 128 (11) ◽  
pp. 1723
Author(s):  
Р.М. Архипов ◽  
М.В. Архипов ◽  
И. Бабушкин ◽  
А.В. Пахомов ◽  
Н.Н. Розанов
Keyword(s):  
Hydrogen Atom ◽  
Key Words ◽  
Spontaneous Emission ◽  
Coherent Control ◽  
Generation Mechanism ◽  
Resonant Medium ◽  
Atomic Polarization ◽  
Short Pulses ◽  
X Ray ◽  
Free Polarization

Recently, for the generation of extremely short pulses, a method was proposed for coherent control of the polarization of a medium, based on the excitation of atomic polarization oscillations and their subsequent arrest using a pair of ultra short pulses. The so-called stopped pulse of polarization of the medium, which appears in the interval between its excitation and de-excitation, can be a source of an extremely short radiation pulse. In this paper, the indicated possibility of generating an isolated attosecond ultraviolet pulse in a three-level resonant medium, the parameters of which correspond to a hydrogen atom excited by a pair of unipolar X-ray pulses, is considered theoretically. In this case, the generation mechanism is "antenna", that is, it is caused by the collective spontaneous emission of pre-phased atoms in the absence of a noticeable decay of their free polarization. Key words: collective spontaneous emission, coherent control of atomic polarization, attosecond pulses, unipolar pulses, X-ray pulses, hydrogen atom.

Plasma Channel Undulator for Narrow-Bandwidth X-Ray Generation

2018 ◽  
pp. 163-166
Author(s):  
S. G. Rykovanov ◽  
J. W. Wang ◽  
V. Yu. Kharin ◽  
B. Lei ◽  
C. B. Schroeder ◽  
...  
Keyword(s):  
Plasma Channel ◽  
X Ray ◽  
Narrow Bandwidth

Design of an X-ray undulator: optimization considerations for SASE operation

2019 ◽  
Vol 97 (11) ◽  
pp. 1177-1181
Author(s):  
Bora Ketenoglu ◽  
Ayhan Aydin ◽  
Omer Yavas
Keyword(s):  
Fourth Generation ◽  
Light Sources ◽  
Generation Process ◽  
Simulation Studies ◽  
Radiation Characteristics ◽  
Short Pulses ◽  
X Ray ◽  
Novel Technology ◽  
Saturation Power ◽  
World Class

Accelerator-based fourth-generation light sources, namely, free-electron lasers (FELs), offer unique radiation characteristics, such as tunable, coherent, high-power, ultra-short pulses. They rely on novel technology with challenging parameters, from which the practicability is currently being proved by world-class facilities like the European XFEL, LCLS, FLASH, and SACLA. When contriving such superior light characteristics, “state-of-the-art” linear accelerator (linac) and undulator technologies come into prominence. In this respect, design and simulation studies for a planar X-ray undulator are considered to optimize the FEL generation process by self-amplified spontaneous emission (SASE). Three main performance parameters for SASE operation (i.e., 1D gain length, saturation power, and saturation length) are compared and discussed by means of numerical calculations and simulation results. It is shown that hard X-ray FEL pulses (down to sub-angstroms) are generable via in-vacuum hybrid undulators driven by an 8 GeV electron linac.

Simulations of femtosecond X-ray diffraction from unperturbed and rapidly heated single crystals

1999 ◽  
Vol 32 (4) ◽  
pp. 692-703 ◽  
Author(s):  
J. S. Wark ◽  
R. W. Lee
Keyword(s):  
Single Crystals ◽  
Time Scales ◽  
X Rays ◽  
Femtosecond Pulses ◽  
X Ray Diffraction ◽  
Similar Time ◽  
Short Pulses ◽  
X Ray ◽  
Laser Sources ◽  
Laser Heated

Simulations are presented of the dynamical diffraction of femtosecond pulses of X-rays from crystals whose structures are modified on similar time scales. Such simulations are of relevance to experiments in which short pulses of X-rays from synchrotron or laser sources are diffracted from rapidly laser-heated crystals.

scholarly journals The free-electron laser FLASH

2015 ◽  
Vol 3 ◽  
Author(s):  
Siegfried Schreiber ◽  
Bart Faatz
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Extreme Ultraviolet ◽  
Laser Flash ◽  
Single Shot ◽  
Short Pulses ◽  
X Ray ◽  
Pump And Probe ◽  
User Facility ◽  
Diffraction Imaging

FLASH at DESY, Hamburg, Germany is the first free-electron laser (FEL) operating in the extreme ultraviolet (EUV) and soft x-ray wavelength range. FLASH is a user facility providing femtosecond short pulses with an unprecedented peak and average brilliance, opening new scientific opportunities in many disciplines. The first call for user experiments has been launched in 2005. The FLASH linear accelerator is based on TESLA superconducting technology, providing several thousands of photon pulses per second to user experiments. Probing femtosecond-scale dynamics in atomic and molecular reactions using, for instance, a combination of x-ray and optical pulses in a pump and probe arrangement, as well as single-shot diffraction imaging of biological objects and molecules, are typical experiments performed at the facility. We give an overview of the FLASH facility, and describe the basic principles of the accelerator. Recently, FLASH has been extended by a second undulator beamline (FLASH2) operated in parallel to the first beamline, extending the capacity of the facility by a factor of two.

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